REPTILIA 



267 



that they may live on land without danger of drying up 

 and even dwell in deserts, but have never attained to tem- 

 perature regulation like the "warm-blooded" animals. 



During past ages, however, the reptiles were a mighty 

 race, and at one time ruled the earth. They were special- 

 ized along diverse lines and during early tertiary times 

 were the dominant animals 'in most of the available habi- 

 tats (Fig. 101). Icthosaurs, plesiosaurs, crocodiles, and 

 mososaurs were admirably fitted to prey upon the smaller 



FIG. 101. Restorations of fossil reptiles. (Adapted from Knipe and Lucas.) 

 A pterodactyl soars through the air, two dinosaurs are walking along the shore, 

 and a mososaur swims in the water. , 



animals in the ocean, before there were whales or dolphins. 

 The empire of the air was ruled by great pterosaurs, which 

 were somewhat like birds in form but possessed teeth and 

 long tails. They had, like birds, many adaptations for 

 aerial life such as wings and hollow bones. One species 

 could spread its wings about twenty feet. The land was 

 inhabited by giant dinosaurs and other reptiles, some 

 exceeding a hundred feetT in length. There was great 



